The present invention relates generally to shoe insoles, and more particularly, to improved gel insoles for shoes that provide both cushioning and spring characteristics.
Insoles have generally been formed by a pad of cushioning material, such as foam or sponge rubber, that has a general shape conforming to the interior of a shoe. Wearers who desire additional shoe comfort or who suffer from foot trouble, for example, plantar heel pain and/or arch pain, insert the cushioned insole into the shoe to provide added cushioning and support.
It is also known to provide gel insoles for shoes. The gel insoles are provided as a movable fluid or as a viscoelastic gel. Because of the viscous nature of the gel, the gel insoles provide shock absorption and consequently protection to the foot. One reason that gel insoles are popular is that they can be made sufficiently thin to fit in shoes. In order to provide comfort, a soft, absorbent top cloth is adhered to the upper surface of the gel insoles.
However, the shock absorbing quality of the gel insoles has a deleterious effect. Specifically, because of the dampening affect of the gel, walking can require more energy, causing the muscles to get tired more easily.
U.S. Pat. No. 5,551,173 to Chambers discloses an insole having oblong protuberances on the upper surface and located in areas corresponding to the reflex zones of the feet, to provide a massaging action thereat. It is further disclosed in this patent that the insoles can be reversed so that the protuberances are on the lower surface of the insoles for the purpose of raising the insoles to provide air circulation. However, because of the composition of the insoles and the shapes of the protuberances, the protuberances do not substantially aid in reducing the energy during walking.
Accordingly, it is an object of the present invention to provide a gel insole that overcomes the problems with the aforementioned prior art.
It is another object of the present invention to provide a gel insole that provides the shock dampening affect of a gel material, while also providing a spring action push-off for walking.
It is still another object of the present invention to provide a gel insole that provides comfort to a person""s feet, without causing the muscles to tire easily.
In accordance with an aspect of the present invention, a removable insole for insertion into footwear, includes a lower layer made of a viscoelastic gel and including a lower surface, an upper surface, and at least one of a toe portion and a heel portion formed from the viscoelastic gel. At least one recess is formed in the lower surface of the toe portion and/or heel portion, each recess having a peripheral side wall and a top wall. A plurality of spaced apart spring walls formed from the viscoelastic gel are provided in each recess, the spring walls being connected with the top wall of the respective recess, and the spring walls having lower edges generally coplanar with a lower surface of the toe portion and/or heel portion which is in surrounding relation to the respective recess. A top cover is secured to the upper surface of the lower layer.
Preferably, when a recess is formed in the heel portion, each of the spring walls has a height in a first direction which is greater than a width thereof in a direction transverse to the first direction.
In one embodiment, each of the spring walls is formed in a generally sinusoidal wave shape, with the plurality of spring walls being in substantially parallel, spaced apart relation. A spacing between adjacent ones of the spring walls is greater than the width of the spring walls. Further, the sinusoidal wave shaped spring walls are connected with the peripheral side wall and the top wall of the respective recess.
In another embodiment, the spring walls are formed as column members, in parallel, spaced apart relation. Each of the column members can have a cylindrical shape, a triangular cross-sectional shape, or any other suitable cross-section. When a recess is formed in the heel portion, each of the spring walls has a height in a first direction which is greater than a width thereof in a direction transverse to the first direction. Also, a spacing between adjacent ones of the spring walls is preferably greater than the width of the spring walls. The spring walls are connected with the top wall of the respective recess.
The insole also includes at least one pattern trim line at the toe portion for trimming the insole to fit into smaller size footwear.
Preferably, the lower layer includes the toe portion, the heel portion and a medial arch portion interconnecting the toe portion and the heel portion, with a first recess with the spring walls in the toe portion and a second recess with the spring walls in the heel portion. In such case, the heel portion has a greater thickness than the toe portion, and the spring walls in the second recess having a greater height than the spring walls in the first recess. Also, opposite sides of the medial arch portion and opposite sides and a rear end of the heel portion gently slope downwardly and inwardly toward the lower surface of the lower layer.
The above and other features of the invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings.